Considerable risk is encountered when technology is scaled up from pilot plant scale to commercial plant scale in order to reap the benefits of economy of scale. Three-phase slurry reactors typically exhibit scale-dependent macro-mixing effects and the aforementioned risk is thus applicable when three-phase slurry reactors are scaled up. It will thus be an advantage if a method can be found which can significantly reduce the risk associated with upscaling of three-phase slurry reactors. In addition, reactor designs in which the mixing patterns inside the reactor can be more readily modelled or predicted from experimentation have the benefit that the extent of usually undesirable back-mixing can be limited thereby potentially allowing an optimal combination of desirable plug-flow characteristics (usually good productivity and good selectivity) and well-mixed characteristics (often required for desirable solids distribution and even temperature profiles).
A solution that has been proposed is to create zones in the reactor that effectively mimic the behaviour of a reactor with a smaller characteristic diameter. In this manner the behaviour of the large scale reactor can be predicted to some extent, since it effectively consists of the sum of a number of smaller reactors of effectively pilot plant scale. However, one is still largely dependent on working within the bounds of the macro-mixing patterns that are established in the reactor with a smaller characteristic diameter. It would thus be an advantage if a method can be found that allows designers additional degrees of freedom to, at least to some extent, control the mixing patterns that are established in a three-phase slurry reactor.
Three-phase slurry reactors are commonly used for highly exothermic reactions due to their excellent heat removal characteristics. However, with the introduction of ever more active catalysts and more intensive use of reactor volume, even the heat removal ability of three-phase slurry reactors is being tested.
In light of what has been said before, it will thus be an advantage if a method can be found which significantly reduces the risk associated with upscaling of three-phase slurry reactors by allowing the designer additional degrees of freedom to exert some control over the mixing patterns in the reactor, while simultaneously increasing the heat removal ability of the reactor.